Following Nielsen’s latest survey that showed over 90 percent of United States smartphone buyers are choosing iOS or Android, research firm comScore today released its data of the top smartphone platforms and OEMs in the U.S. The survey included more than 30,000 people over a three-month period ending February 2012. It found Android was up 17 percentage points from a year ago with 50.1-percent of the U.S. smartphone market. In comparison, Apple’s 30.2-percent accounted for an increase of 5 percentage points from the same period a year ago.

According to comScore, Google passed the 50 percent milestone for the first time during February 2012. The numbers represent a 3.2-percentage point increase over previous three-month period for Google, and a 1.5-percentage point increase for Apple.

When it comes to the top mobile phone manufacturers (including non-smartphones) in the U.S., Samsung takes the top spot with 25.6-percent of the market for the three-month period ending February 2012. LG was close behind with 19.4-percent, followed by Apple with 13.5-percent, Motorola at 12.8-percent, and HTC at 6.3-percent.

During the period, Apple experienced the highest market share increase up 2.3-percentage points compared to the previous three-month period and passed Motorola to grab the third highest share of the U.S. smartphone market among OEMs. Nielsen’s numbers for the total number of smartphone owners during the period were almost identical to comScore’s. However, Nielsen’s data shows that when looking at just new smartphone purchasers, iOS and Android’s combined marketshare rises from roughly 80 percent to over 90 percent as of February 2012.